In oil and gas drilling operations, hydrocarbon producing wellbores extend subsurface and intersect subterranean formations where hydrocarbons are trapped. The wellbores generally are created by drill bits attached to the end of a drill string, where typically a drive system above the opening to the wellbore rotates the drill string and bit. Drill bits are usually equipped with cutting elements that scrape the bottom of the wellbore as the bit is rotated to excavate material from the formation, thereby deepening the wellbore. Drilling fluid, also referred to as drilling mud, is typically pumped down the drill string and directed from the drill bit into the wellbore, where it then flows back up the wellbore in an annulus between the drill string and walls of the wellbore. The drilling fluid cools the bit, maintains a desired pressure in the well, and when flowing up the wellbore carries with it cuttings produced during drilling operations.
Safe and efficient hydrocarbon well drilling practices are essential in the oil and gas industry. Among the most costly and challenging problems encountered in the industry involves the occurrence of lost circulation zones or “loss zones” in a wellbore. This phenomenon generally results from the drilling fluid flowing from the wellbore into the subterranean formations where the hydrocarbons of may be trapped. The resulting reduction or loss of flow in a well affected by lost circulation, which can exceed 100 bbl/hr, is detrimental in terms of both the financial loss and the resulting safety concerns, which may include the potential loss of well control. The elimination or alleviation of lost circulation zones is a priority for the industry, as billions of dollars are lost per year due to lost circulation in drilling operations through losses of drilling fluids, formation damage (e.g., if losses occur include reservoir section) and its negative impact on hydrocarbon production, and the costs of addressing the phenomenon through, e.g. lost circulation materials (LCMs). In further consideration of the relevant potential environmental and regulatory issues, the prevention and remediation of circulation loss in drilling operations is highly desirable.